It recharges about 20% per day, technically you can give 10-11 full votes per day if you're trying to maximize the output of value (say when you're getting close to 100% voting power, let's say 99.99%, you cast one vote, you then wait 2-3h to cast the next 100% vote at 99.99% voting power, etc) but there's not a lot of point to this method as you don't profit from it more, it's just about how big of a vote you want to give others.

Voting power is quite flexible, if you are at 50% voting power and cast a 100% vote, it's technically just a 50% vote but instead of burning 2% voting power as it would do at 100% voting power, it only burns 1% so you get back to 50% voting power twice as fast as if you wanted to wait to get to 100% voting power.

It can get complicated to explain it, but basically keep it between 80 and 90% and do 10 full votes per day or 20x 50% votes per day or 40x 25% votes per day, etc. The important thing for yourself is to not let it sit at 100% voting mana as that may cause you to lose out on potential curation rewards.